Is it possible now to determine genetic traits that you grandfather had, from your own genetic material?
Yes, no, or kind of?

'Kind of' would mean you can tell the genetic traits of your grandparents - of that generation, rather than individuals of that generation. So a certain genetic trait popped up at that generation, but it's impossible now to tell who provided it.

RE: Can genetic testing tell you the genetics of a specific generation?

My paternal grandmother had a certain bend or twist that was particularly evident in her ring and middle fingers. They were kind of bowed together. It's hard to explain but the middle fingers also tended to twist toward the ring finger. The little fingers were also quite short.

My father and his siblings had the same finger shape. So do my siblings and I (not sure about the cousins). It has passed to my kids and to my grandkids.

I am not sure how far back it went from grandma but it sure has carried on a while since her.

My son has a cleft chin that he got from his dad...his half sister on his dad's side also has it. But he also has the unique sky blue eye color that passed from my maternal grandfather, down through me, to him.

I think you can trace certain genetic traits, and the dominance of certain genes, through generations...sometimes quite easily.

See here they are, the bruises, some were self-inflicted and some showed up along the way. - JF